The present disclosure relates to the lens fabrication arts. It finds particular application in connection with a lens for correcting discrimination of color by a patient (or color blindness as it is commonly known) and for alleviating symptoms of dyslexia through a colored lens prescription. However, it is to be appreciated that the exemplary lens and fabrication method are not limited to such applications and may find application in the selective adjustment of light transmission through a lens for other purposes.
In the field of opthalmology, it has been found that by providing lenses which selectively filter the incident light in the visible region of the spectrum, e.g., from about 650 nm (red region) to 475 nm (blue region), particularly in the shorter (blue) wavelengths, the light received through the lens is thereby modified so as to affect the manner in which it is handled neurologically, by the viewer. Lenses have been produced for patients suffering from color blindness which are individually color tinted for the characteristics of a patient's vision. Such corrective lenses enable the patient to train their optical discernment to perceive colors correctly and also to address many of the symptoms of dyslexia. The technique of providing individually tinted lenses for a patient's eye for correcting color discrimination thus results in the patient having corrective lenses of different color tint indicating the purpose of the correction to observers and results in a cosmetically unacceptable appearance. To render the appearance more acceptable, U.S. Pat. No. 6,089,712 discloses a lens of this type, where a central portion of the lens is tinted with the desired color correction for the individual eye and the outer surface of the lens is coated with a mirrored reflective material to make the color tinting invisible to an outside observer. The technique described in the '712 patent provides the desired color correction. However, the presence of the mirror reflective surface on the lens has been found to be cosmetically unacceptable to some. Additionally, the mirrored surface may reflect such a high percentage of light that the spectacles may produce an image that is too dark for the wearer.
Thus, it is desired to provide color corrective lenses for patients with color blindness or dyslexia to treat the disability but in which the color tints are not discernible to an outward observer and which are not prohibitively costly.